Mycology and Phytopathology

The study examines the features of the formation of mycobiota in coal mine spoil tips of different ages using metagenomic data. The purpose is to explore the dynamics of fungi complexes during the succession process in the arctic tundra, southern tundra, and forest-tundra. Samples were taken from coal mine spoil tips in Barentsburg (Svalbard), Vorkuta (Komi Republic), and Susuman (Magadan Region). The results show that the diversity of fungi is mainly represented by Ascomycota. A high proportion of Eurotiomycetes, Dothideomycetes, Leotiomycetes, Agaricomycetes, and Sordariomycetes was found in the chronoseries of the spoil tips. At the genus level, 58 taxa were identified in the Svalbard chronoseries, 59 taxa in the Komi chronoseries, and 65 taxa in the Magadan Region chronoseries. The studies demonstrates that the fungal communities in coal mine spoil tips are diverse and change depending on the age of the tips and the natural zones of the Arctic. It has also been shown that communities of spoil tips within one chronoseries have greater similarities with each other than with communities of spoil tips in other natural zones.

The results of the first micological studies of the territory of the “Karansky” State Nature Landscape Sanctuary (Sevastopol City), carried out in 2022–2023, are presented. The sanctuary was established in 2017 and is the first site in the region’s network of specially protected natural areas to undergo regular mycological surveys covering all seasons of the year. Mycobiota was studied in the territory of three designated stationary clusters of the sanctuary with different types of vegetation using the route method. Samples were collected during all seasons at intervals of three to 10 days, with photo fixation of carpofores in the natural environment. A total of 388 herbarium samples were collected and identified using light microscopy methods with a standard set of chemical reagents, taking into account the nature of the vegetation at the collection site. Annotated list contains 182 species of macrofungi from 92 genera, 45 families, 13 orders and five classes, including 9 ascomycete and 173 basidiomycete species (agaricoid – 140, gasteroid – 9, aphylloforoid – 24). For the macrofungi of the sanctuary ecological-trophic structure, biotopic location, diversity of geo-elements and ranges, as well as seasonal dynamics of the formation of fruit bodies are characterized. Ninety-one species (50% of the total) were identified in the Sevastopol region for the first time, of which 10 species are newly reported for the Crimea Peninsula (Agaricus comtulus, Mycena filopes, Marasmiellus candidus, Gymnopus impudicus, Phloeomana speirea, Clitocybe agrestis, C. fragrans, Exidia nigricans, Rheubarbariboletus armeniacus, and Phaeotremella frondosa). Fifteen species are classified as rare, two of which are included in the Red data book of the Russian Federation (2024), and four species are represented in the Red data book of the city of Sevastopol (2018). For the protected macrofungi (Amanita vittadinii, Ganoderma lucidum, Hemileccinum depilatum, and Tuber aestivum) a brief description, information on population size and distribution are provided. The mycobiota of the “Karansky” Nature Sanctuary is classified as a forest-steppe type mycocomplex with a predominance of agaricoid fungi of soil mycosynusia and the formation of fruiting bodies mainly in the autumn-early winter period. Data on thermophilic species are of interest for clarifying the boundaries of their global ranges. The results obtained confirm the importance of the “Karansky” Nature Sanctuary for the conservation of regional mycobiotic diversity and provide a basis for recommendations on optimizing the nature conservation regime of the sanctuary.

Wood-destroying fungi of the genus Ganoderma are among the most widespread polypore fungi in the world. The interest in their study is constantly growing due to the fact that they are producers of many biologically active substances. The most common species in central Russia is the artist’s bracket fungus, Ganoderma applanatum. The purpose of our study was to characterize G. applanatum intraspecific genetic polymorphism of sexual and somatic compatibility, as well as ITS sequence variability based on the collection of 26 natural specimens collected in various Moscow localities in 2022 and 2015. The technique developed for obtaining a sterile fertile hymenium on Petri dishes in vitro was applied for genetic analysis of mating type alleles by mon-mon and di-mon crossings. For analyzing mating compatibility alleles, the monokaryotic tester strains were obtained in mon-mon crossing for five natural isolates of the collection. Sexual compatibility of the rest natural dikaryotic isolates were tested in di-mon crossing. The mon-mon crosses demonstrated tetrapolar heterothallism in G. applanatum, governed by two unlinked mating type loci, and the di-mon crosses of natural isolates via monokaryotic testers revealed multiple alleles for each locus. Among the 21 natural isolates of G. applanatum, at least 8 alleles of the matA locus and 7 alleles of the matB locus were characterized. However, no intersterile groups were found within the species G. applanatum. Semi-compatibility in mon-mon crosses of the testers, i. e. heteroallelicity at the A-locus and similar alleles at B-locus were revealed for two dikaryotic isolates collected on the same log at a distance of two meters. Somatic compatibility was tested by pairwise splicing of dikaryotic mycelia in all possible combinations between all Moscow strains collected in 2022 and 2015. The contact zone and interaction phenotype were analyzed by estimating the degree of antagonistic reaction between the contacting mycelia: C – compatibility, W – weak antagonism; M – moderate antagonism; S – strong antagonism. Compatible somatic clones were found only within the substrate. Strong (S) antagonistic interactions with a relatively wide (2–3 mm) zone of confrontation and intense pigmentation predominated among paired isolates (with frequency of 0.46). Interestingly, six strains collected from a fallen coniferous tree of 3.5 m long were apparently vegetatively compatible clones, two of those strain having identical mating compatibility alleles. The estimated genetic variability of somatic incompatibility antagonistic responses was Hvc = 1.216 by Shannon index, that indicates on rather high level of genetic polymorphism of the determinants of somatic incompatibility as well as on multiple alleles at somatic incompatibility loci. Our results are consistent with data obtained for the Ganoderma species of southern latitudes such as the agents of palm rot G. boninense and G. zonatum. Despite of the genetic polymorphism and multiallelicity of sexual and somatic incompatibility loci, ITS sequences among G. applanatum isolates demonstrated conservatism and the lack of divergence. There was no obvious differentiation on strain origin, substrate specificity, or collection time. Phylogenetic analysis also demonstrated the lack of divergence and identity of ITS sequences among G. applanatum strains from the Moscow region, as well as strains from St. Petersburg area. Therefore, the G. applanatum population in Moscow Region is concluded to be distributed over a quite large area with the little intrapopulation differentiation. However, ITS sequences are suggested to be a reliable molecular barcode for species identification/verification of G. applanatum natural specimens.

The search for new methods for activating and controlling the enzymatic activity of cellulose destructor organisms through joint cultivation is relevant. Schizophyllum commune is a basidiomycete from the group of white rot fungi, known for its biotechnological versatility. It has not yet found effective application in the field of bioconversion of agricultural waste, in particular, straw of cereals. An assessment of the possibility of creating based on a strain S. commune EO22 artificial bacterial and fungal associations for the development of an effective strategy for the utilization of straw, a by-product of crop production. The effects of co-cultivation of S. commune EO22 with cellulolytically active bacteria of the genus Streptomyces were studied. The dynamics of cellulase activity was determined during the cultivation of S. commune EO22 fungus in monoculture and in binary cultures with strains Streptomyces griseoaurantiacus Mb4-2, S. thermocarboxydus T1-3, S. hygroscopicus N27-25, “S. ryensis” H13-3. Binary crops were grown in a liquid mineral medium with straw as the only carbon source. The enzyme activity was measured in a culture liquid supernatant at 50°C and pH 5 according to the initial rate of formation of reducing sugars, the concentration of which was determined spectrophotometrically at 540 nm with a reagent based on 3,5-dinitrosalicylic acid. As a unit of activity, such an amount of enzyme was taken, when exposed to the substrate in an enzymatic reaction, 1 micromole of reducing sugars in terms of glucose equivalent is formed in 1 hour. The cellulase activity of Schizophyllum commune EO22 joint cultures with each of the bacterial strains reached a maximum 3–6 days earlier than in the monoculture of the fungus (maximum reached on the 7th day) under the same conditions. When the fungus was co-cultured with the Mb4-2 strain, there was no significant increase in cellulase activity (122 ± 13.1 units/ml) compared with the monoculture of the fungus (114.4 ± 37.1 units/ml). The maxima of cellulase activity of binary associations with strains T1-3, N27-25 and H13-3 exceeded the maximum of the S. commune EO22 monoculture by 2.3, 1.6 and 1.3 times, respectively. The degree of decomposition of straw, determined by weight loss, increased by 10.3, 2.3 and 22.4%, respectively, compared with the monoculture of the fungus. There was no statistically significant correlation between a decrease in straw weight and cellulase activity under experimental conditions. The results obtained indicate the prospects of creating artificial bacterial and fungal associations for the effective destruction of straw and other cellulose-containing waste from crop production.

In recent decades, there has been an increase in the severity of yellow rust of wheat worldwid (caused agent Puccinia striiformis f. sp. tritici). The aim of this work is to characterise the virulence and molecular polymorphism of Russian Pst populations in 2023. Leaves with P. striiformis f. sp. tritici urediniopustules were collected in the North-Western (Leningrad Region), North Caucasus (Dagestan, Krasnodar Territory) and Lower Volga regions (Saratov Region). Fourteen isogenic lines (AvocetNIL) and 15 differentiator varieties served as virulence testers. Twenty markers from Global Rust Research Centre were used in the microsatellite analysis. SCAR markers (SCP19M: 24a1, 24a2, 26a1, 26a2) were involved to search the invasive races PstS1 and PstS2. Virulence analysis included 70 isolates: 34 from Dagestan, 12 from Krasnodar, 6 from Saratov and 18 from Leningrad. The genes Yr5, Yr10, Yr15, Yr24 and Yr26 were characterized by high efficiency. An increase in virulence was noted for the Yr17 gene, which was previously effective in Russia. No significant changes in virulence frequencies were detected for the other Yr genes. Regional Pst populations in 2023, as well as in 2019–2022, were characterized by high phenotypic diversity. Forty-three phenotypes (races) were detected (23 in Dagestan, 3 in Krasnodar, 2 in Saratov and 17 in Leningrad). Two common virulence phenotypes were observed in the Krasnodar and Leningrad Pst collections. According to the Fst index, the Dagestan, Krasnodar, and Leningrad populations were characterized by high similarity; the Saratov population was moderately differentiated from them. Microsatellite analysis was performed for 55 isolates (28 from Dagestan, 18 from Leningrad, 6 from Krasnodar, 3 from Saratov). Polymorphism was noted for 10 out of 20 loci studied, and two alleles were detected in each of them. Significant deviations from the Hardy-Weinberg equilibrium were observed for 11 loci. Genotypic diversity of geographical populations for microsatellite loci was lower than by virulence test. The studied collection was represented by 20 multilocus genotypes (MGs) (Dagestan – 14, Leningrad – 7, Krasnodar – 2, Saratov – 1). Common MGs were found in Dagestan, Krasnodar and Leningrad Pst collections (MG_1); in Dagestan and Leningrad (MG_2); in Dagestan and Saratov (MG_3). Three MGs (4–6) were represented by two or more isolates, the rest by one isolate. As in the virulence analysis, the Dagestan, Krasnodar and Leningrad populations were characterised by high similarity in SSR markers (F_st index); the Saratov population differed moderately from them. According to Mantel’s test, there was a high correlation between virulence and microsatellite results (r = 0.93). Using SCAR markers, as in previous years, single isolates of PstS2 were identified in the Leningrad and Dagestan populations. The conducted complex analysis indicates high variability of yellow rust pathogen populations in Russia, which necessitates annual analyses of their polymorphism in virulence and SSR loci. Donors of highly effective Yr-genes can be recommended for use in breeding for resistance to yellow rust. The lack of differentiation between North Caucasian and Northwestern Pst samples indicates the existence of a single population in these territories.

The mycological herbarium within the V. L. Komarov Botanical Institute of the Russian Academy of Sciences, St. Petersburg, Russia (LE F) contains 6307 specimens of lichenicolous fungi representing 667 species in 197 genera, which covers about a quarter of the known species and about half of the genera in this group of fungi. This assemblage it on a par with the world’s largest collections of lichenicolous fungi such as the herbaria at the Museum of Evolution, Uppsala University (UPS), Meise Botanic Garden (BR), and Botanische Staatssammlung München (M). The LE F herbarium contains holotypes, isotypes, epitype and neotype of 131 species and 5 varieties of lichenicolous fungi, which represents about 5% of their known species diversity. The majority (73%) of specimens were collected from the mid-1990s onwards, when a focused study of this group of fungi was initiated in the Russian Federation. However, there are also some historical specimens collected in the 19th century. One hundred and eighty-eight (3%) specimens entered the herbarium as part of the exsiccate. The largest number of specimens (71%) were collected in the Russian Federation, but there are also specimens from 33 other countries, the most represented being Mongolia, United States of America, Canada, and Norway. The main principals of the 326 specimen collectors are M. P. Zhurbenko (52% of specimens), I. I. Makarova (5%), N. V. Matveeva (3%), D. E. Himelbrant (3%), and V. P. Savicz (2%). Sufficient representation of the sample of lichenicolous fungi specimens in the LE F herbarium has made it possible to make major generalizations, such as checklists of lichenicolous fungi of Russia and Mongolia and an annotated catalogue of lichenicolous fungi of the Russian Meta-arctic. The information on these specimens is available on the Internet and is an important source of information for the preparation of a worldwide “Flora of Lichenicolous Fungi”.